Swelling-activated chloride currents in a drug-sensitive cell line and a P glycoprotein-expressing derivative are underlied by channels with the same pharmacological properties

It has been proposed that P glycoprotein (Pgp) expression is associated with swelling-activated Cl- currents in multidrug-resistant cells. The Pgp substrate vinblastine and the modulator verapamil produced a reversible concentration-dependent block of swelling-activated Cl- currents in both a drug-sensitive cell line (MCF-7) and a Pgp-expressing derivative (BC19/3). The similarity of the results obtained in both cell lines suggests that the mechanism of block is not related to Pgp expression and supports the hypothesis that Pgp expression is not necessary for the swelling activation of Cl- currents. In contrast to the results obtained with vinblastine, two other cytoskeleton-disrupting agents, colchicine and cytochalasin D, were not able to affect the swelling-activated Cl- currents in either cell line. The data provided no evidence for the involvement of the cytoskeleton in the swelling activation of Cl- channels in these cell lines. The Cl- channel blockers, 5-nitro-2-(3-phenylpropylamino)benzoic acid and 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid, each produced a similar reversible concentration-dependent block in the swelling-activated currents in both the Pgp-expressing and nonexpressing cells. This strongly suggests that the Cl- channel(s) responsible for the swelling-dependent current in both cell lines are the same and, since MCF-7 cells do not express Pgp, that Pgp is not the channel responsible for the volume-activated Cl- currents in these cells.     

On the Importance of Cognitive Evaluation as a Determinant of Interpersonal Attraction.

Three studies examined a model of attraction in which the cognitive evaluation of the target individual was the primary determinant of interpersonal attraction. In Study 1, the cognitive evaluation of the target individual mediated the influence of attitude similarity on interpersonal attraction. In Study 2, a path analysis revealed significant indirect effects of (a) similarity on cognitive evaluation via the valence of information implied by attitudes and (b) the valence of information implied by attitudes on attraction via cognitive evaluation of the target. Study 3 provided empirical and theoretical support for the uniqueness of interpersonal attraction from cognitive evaluation. The implications of these data for existing attraction theory are discussed, and a new model of interpersonal attraction is described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cytokine inducible matrix metalloproteinase expression in immortalized rat chondrocytes is independent of nitric oxide stimulation

The objective of this study was to determine if an immortalized mammalian chondrocyte cell line had a profile of matrix metalloproteinase (MMP) expression that was consistent with what has been reported for primary chondrocytes in vitro and in vivo. A combination of zymography, Western, and Northern analysis was used to examine the expression of MMPs that are relevant to cartilage degradation. Both interleukin-1beta and tumor necrosis factor alpha induced a 4- to 9-fold increase in the level of MMP-9 expression in conditioned media, and a 17- to 24-fold increase in MMP-3 mRNA. Other compounds such as basic fibroblast growth factor and staurosporine each increased MMP-9 expression individually and potentiated the effects of the two cytokines. Transforming growth factor beta had no positive or inhibitory effects. N-methyl arginine blocked the increase in nitric oxide observed following treatment with the cytokines but did not prevent the increased expression of MMPs. The pattern of metalloproteinase expression observed in IRC cells and the response to cytokines is very similar to what has been reported during the pathogenesis of osteoarthritis. The IRC cells should be useful as a model system to study basic mechanisms controlling chondrocyte MMP expression and to identify pharmacological modulators of this process.     

Hope and social support as resilience factors against psychological distress of mothers who care for children with chronic physical conditions.

On the basis of the multivariate conceptual model proposed by J. L. Wallander et al (1989), perceptions of hope and social support were hypothesized to serve as resilience factors against distress in mothers of children with chronic physical conditions. Relationships among these variables were tested. Ss were 111 mothers of 5 to 18-yr-old children who had cerebral palsy, spina bifida, or insulin-dependent diabetes mellitus. Tests used included the Hope Scale, Social Support Questionnaire-6, Brief Symptom Inventory, and Parents of Children With Disabilities Inventory. There were no differences in distress among mothers raising children with different conditions. Both hope and social support were associated negatively and uniquely with distress in these mothers. Perceptions of hope moderated the relationship between disability-related stress and maladjustment, suggesting a buffering effect when stress is high. However, hope did not appear to be a mediator of the relationship between social support and distress. These findings enhance our conceptual understanding of distress in maternal caregivers of children with a chronic physical condition. They also support improving sense of hope as is done in some problem-solving training programs to enhance coping in distressed individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characteristics and correlates of fatigue after adjuvant chemotherapy for breast cancer

PURPOSE: Clinical reports suggest that many breast cancer patients experience persistent fatigue as a long-term side effect of adjuvant chemotherapy treatment. To investigate this issue further, we examined the characteristics and correlates of fatigue in women who had completed adjuvant chemotherapy for breast cancer and in a comparison group of women with no history of cancer. PATIENTS AND METHODS: Participants were 61 women with breast cancer who had completed chemotherapy an average of 471 days previously and 59 women with no history of cancer. All participants completed standardized self-report measures of fatigue, sleep quality, menopausal symptoms, and coping and were administered a structured clinical interview to identify current and past psychiatric disorder. RESULTS: Compared with women with no history of cancer, former adjuvant chemotherapy patients reported more severe fatigue (P < .01) and worse quality of life because of fatigue (P < .05). More severe fatigue among patients was significantly (P < .05) related to poorer sleep quality, more menopausal symptoms, greater use of catastrophizing as a coping strategy, and current presence of a psychiatric disorder. CONCLUSION: These findings support the view that many breast cancer patients experienced heightened fatigue after completion of adjuvant chemotherapy treatment. Results yield a profile of women who are at increased risk for heightened fatigue after chemotherapy and suggest ways to intervene clinically to prevent or reduce fatigue in this patient population.     

Smoking.

The task force on cigarette smoking research in health psychology addressed three questions: What are the major current research directions of health psychologists on this topic? What are the major future research directions that health psychologists should address on this topic? What barriers to smoking research exist for health psychologists? Discussion of current research focused on five areas: prevention, cessation, relapse, basic science research, and public policy. Smoking prevention research centers on school-based interventions in longitudinal trials targeting adolescent substance abuse--including cigarette smoking--and focusing on the processes influenced by the intervention that, in turn, prevent smoking. Research also is being conducted outside the school setting to test community-wide public information campaigns and to reach adolescents in other social groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early antenatal ultrasound diagnosis of fetal intracranial teratoma

The commonest fetal intracranial tumour is a teratoma. The prognosis is poor with death usually occurring shortly after birth. Modern high resolution ultrasound scanners facilitate examination of the cranial contents, allowing earlier diagnosis. We report a case where an intracranial teratoma was identified at 21 weeks gestation, the earliest gestational age that this has been reported. The ultrasound appearances are discussed.     

Social psychological factors in the genesis of posthypnotic source amnesia.

Three experiments assessed the role of social psychological variables in source amnesia. Experiment 1 found that low-hypnotizable subjects instructed to simulate partial amnesia were more likely to exhibit source amnesia than high-hypnotizable hypnotic or task-motivated subjects. Experiment 2 found equivalent rates of source amnesia in low-hypnotizable simulators and high-hypnotizable hypnotic subjects. In addition, the findings of Experiment 2 failed to support the idea that the instructions for partial amnesia given to simulators cued for the occurrence of source of amnesia as well as for the occurrence of partial amnesia. In Experiment 3, preliminary instructions that legitimated source amnesia as a role-appropriate response produced significantly more posthypnotic source amnesia than did neutral or no instructions. Together, the findings of the 3 experiments support the relation of source amnesia to experimental demands and subjects' expectations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)